1. Field of the Invention
This invention relates to polymerizable compositions comprising an energy-polymerizable catalyst system, and cured adhesive films, pressure sensitive adhesives, protective coatings, liquid adhesives, structural and semi-structural adhesives, and free-standing films prepared therewith.
2. Description of the Related Art
Various polymeric coatings and articles are produced in processes involving the use of organic solvents. There is an intense effort by researchers and industry to promote high and 100% solids formulations and processes to reduce or eliminate the use of such solvents and the attendant costs and environmental contamination.
Radiation dual curable compositions containing unsaturated monomers and epoxy monomers have been described in a number of U.S. Pat. Nos. 4,156,035 (Tsao et al.), 4,227,978 (Barton), 4,428,807 (Lee et al.), 4,623,676 (Kistner), 4,657,779 (Gaske), and 4,694,029 (Land). Compositions described in the aforementioned patents include onium salts combined with organic compounds as the curing system.
U.S. Pat. No. 4,717,605 (Urban et al.) describes radiation curable adhesives based on the combination of an epoxide system and ionic photoinitiators of the triarylsulfonium complex type and at least one ethylenically unsaturated substance that can be polymerized by free radicals and at least one free radical photoinitiator. The adhesive described is a hardenable glue cured by two light exposures.
U.S. Pat. No. 4,677,137 (Bany et al.) describes a process using a supported onium salt or an ionic salt of an organometallic complex as the photoinitiator system for the polymerization of cationically polymerizable materials.
U.S. Pat. No. 4,707,432 (Gatechair et al.) describes a free radically polymerizable composition comprising a free radically polymerizable material and a photoinitiator system comprising an alpha-cleavage or homolytic bond cleavage photoinitiator and a ferrocenium salt.
WO 8802879 (Woods et al.) describes a free radically polymerizable composition comprising a free radically polymerizable material and a photoinitiator system comprising a free radical photoinitiator and a ferrocenium salt. Furthermore, the composition may contain one or more cationically polymerizable materials.
U.S. Pat. No. 4,849,320 (Irving et al.) describes a process using a combination of two different photoinitiators and two different polymerizable monomers in combination with irradiation at two substantially different wavelengths.
U.S. Pat. No. 4,751,138 (Tumey et al.) describes a coated abrasive article prepared by polymerizing a combination of epoxy and acrylate monomers using a combination of photoinitiators that can be a ferrocinium, onium salts or an alpha-cleavage or homolytic bond cleavage photoinitiator.
AU 8538551 (Meier et al.) describes a curable composition containing materials that are polymerizable by free radical or cationic mechanisms using an iron containing cationic organometallic compound and an electron acceptor as an oxidizing agent. The electron acceptors are preferably an organic hydroperoxide, an organic peracid or a quinone. The utility of this composition is in the preparation of protective coatings, adhesives, putties, or fiber reinforced composites and laminates.
U.S. Pat. No. 3,907,706 (Robins) describes a catalyst system comprising a metal salt of a fluoroalkane sulfonic acid and a thermally decomposable ester reaction product of a tertiary alkyl alcohol and an acid that forms a chelation complex with the metal ion of the metal salt. In some embodiments, the catalyst system includes a buffering compound that retards activity of the catalyst system.